G506 engine problems

[FlavaFrav6]

Hello im new to this forum and am seeking advise on an engine problem we are facing with our 1 1/2 ton chevy. The truck was restored by my father then put away for some years. About 3 years ago we got it back out and had it running fine. However it took a dive and we havent been able to get it running smoothly since. It has a brand new carburetor so i kno that is not the problem. My father also made a coffee can with a fuel line attached some years ago to by pass any fuel pump or line problems. My problem is that we can get the truck running for a few minutes but as soon as u go to give it gas it starts to flutter and then dies out. It seems like its not getting gas but i have disassembled the carb. and the float and needle work fine plus i removed and inspected all the jets which were fine to. This leads me to believe that there is an ignition problem. Has anyone else experienced this problem that might have some advise. Thanks lets keep em runnin.

[pfarber]

When it cuts out does it start back up immediately?

Have you read the spark plugs?

When you are giving it gas, is someone at the distributor to adjust timing?

Best starting point is to do a complete tune up. Points/plugs/wires (you can keep the old parts as spares). Set the timing by the marks and go from there.

Do you have a vacuum gauge? That will tell you a lot about how the engine is performing.. and GREATLY ASSIST in timing. Also an strobe light with tachometer can be of great help.

And this may be in left field.. but you have a vent on your 'gas coffee can'?

[FlavaFrav6]

Yea when i cuts out i can usually get it running right again. The first few pumps of the gas peddle let the engine rev but if i continue to give it gas it flutters and chokes itself out. I have not checked all the plugs but i think the next step would be to install modern day ignition that are of the correct cross number. Everything on it now is new old stock b/c at the time my father was restoring it to show quality. Id like to check the timing however our light seems to be from the 50's and the six volt system doesnt provide enough light to accurately see the timing marks. I do think it is out of time though b/c it ran fine before. i dont see how it could have jumped time. I guess my next step would be to change plugs, condenser, points, wires, and possibly a new coil. i just hope that the voltage regulator couldnt be the culprit idk if it has anything to do with the ignition or not. Thanks for the advice keep it coming if u think it will help.

[pfarber]

The voltage regulator would not have anything to do with the ignition. The battery is the primary supply for the ignition system. You don't need a genny/regulator as long as you have a good 6v battery fully charged.

Since it starts right back up I also don't think its fuel related... BUT there are separate carb fuel circuits involved from idle and at speed. When you said the carb was rebuilt.... were the channel plugs pulled and the passages cleaned or just the jets/seats changed? You could have a restricted high speed circuit that idles, but won't pass enough fuel to sustain higher RPMs.

The distributor needs to have the points set properly. Make sure that dist. weights and springs and moving freely (they change the timing as RPM increases). Also check the rotor and cap for carbon arcs.

I had a heck of a time with my 539S on my jeep cutting out.. I had a dirty tank and had run without the fuel filter in place... dirt got into the bowl, and had clogged the main jet passage that required popping all the passage rivets. The jet was clean, but the 90 degree turn in the fuel passage had gunk in it... enough to stumble the carb and cut it out above 30 mph.

Save the deep digging til all the easy stuff is ruled out... but don't rule out anything unless you have physically determined that that's not where the fault lies.

[FlavaFrav6]

since my last post i have replaced points and set them correctly, new condenser, new plugs. the coil and wires were replaced about two years ago before the truck sat. i have also timed the engine. the truck runs great at idle however it is still stumbling when i go to give it gas. I have checked compression and vacuum and they are both good. i have also removed the muffler in thought that i might have a blockage. the only thing left is to tear apart the carburetor again to check for blockages then maybe try to bypass the governor. I am not sure if the passages in the carburetor were removed but the inside looks very clean. I had it apart two weeks ago and couldnt find any problems. Also two years ago when we started having these problems we were using a different carb. the one on it now was ordered off the internet from a company that rebuilds them. If any one has any further advise i would greatly appreciate it.

[pfarber]

You could also double check your accelerator pump. Most carbs will give an extra squirt of gas to get it to transition off idle to at speed. They usually need to be set properly and timed.

I don't know what TM covers the Carter W1 carb ( I *think* thats the model used on G506's) and go through that.

Its 50/50 if the carb shop removed the plugs to clean *all* the passages. Some don't want the hassle of taking them out and reinstalling them.... but soaking in solvent doesn't do as good a job as most people think it does.

Get them TM, check the linkage settings.. it sounds like a really, really bad off idle stumble (lots of new jeep owners suffer from this till they read the TM or post about it).

[FlavaFrav6]

After many long hours and frustrating days i have resolved the issue. I removed the components from the distributor to check the weights underneath. When i went to re-install the condenser and points i decided to try out the old one to see if they would make a difference. Low and behold the truck fired right up idled and accelerated. When i replaced the points i used the cross over number for napa found on the vehicles of victory web site however the points were not exactly the same. Thanks for all the input im glad ive finally figured it out.